Closed
Description
What version of Go are you using (go version)?
$ go version go1.14 linux/amd64
Does this issue reproduce with the latest release?
Yes.
What operating system and processor architecture are you using (go env)?
go env Output
$ go env
What did you do?
I built a version of my program with a minor code change, and for the first time switching from the go 1.13 compiler to go 1.14. I then deployed that version of the program to my staging environment, all linux/amd64 machines.
What did you expect to see?
The program to start up normally on all hosts.
What did you see instead?
On about half of the hosts, the program crashed on startup with slight variations on this message:
runtime: pointer 0xc0034fbd40 to unused region of span span.base()=0xc006bf2000 span.limit=0xc006c67300 span.state=1
runtime: found in object at *(0xc000425110+0x28)
object=0xc000425110 s.base()=0xc000424000 s.limit=0xc000425fb0 s.spanclass=28 s.elemsize=208 s.state=mSpanInUse
*(object+0) = 0x1010100000080
*(object+8) = 0xc0034fb980
*(object+16) = 0x8726ce
*(object+24) = 0x0
*(object+32) = 0x0
*(object+40) = 0xc0034fbd40 <==
*(object+48) = 0xc0a6c8
*(object+56) = 0xc0034fbaf0
*(object+64) = 0x872431
*(object+72) = 0x0
*(object+80) = 0x0
*(object+88) = 0x0
*(object+96) = 0x0
*(object+104) = 0x0
*(object+112) = 0x0
*(object+120) = 0x0
*(object+128) = 0x0
*(object+136) = 0x0
*(object+144) = 0x0
*(object+152) = 0x0
*(object+160) = 0x0
*(object+168) = 0x0
*(object+176) = 0x0
*(object+184) = 0x0
*(object+192) = 0x0
*(object+200) = 0x0
fatal error: found bad pointer in Go heap (incorrect use of unsafe or cgo?)
runtime stack:
runtime.throw(0xbc9a25, 0x3e)
/opt/go/src/runtime/panic.go:1112 +0x72 fp=0x7fb9c77fdd30 sp=0x7fb9c77fdd00 pc=0x436132
runtime.badPointer(0x7fba3c4cf108, 0xc0034fbd40, 0xc000425110, 0x28)
/opt/go/src/runtime/mbitmap.go:380 +0x230 fp=0x7fb9c77fdd78 sp=0x7fb9c77fdd30 pc=0x416410
runtime.findObject(0xc0034fbd40, 0xc000425110, 0x28, 0x7fba3c659d20, 0xc000036e98, 0x7)
/opt/go/src/runtime/mbitmap.go:416 +0x9b fp=0x7fb9c77fddb0 sp=0x7fb9c77fdd78 pc=0x4164bb
runtime.scanobject(0xc000425110, 0xc000036e98)
/opt/go/src/runtime/mgcmark.go:1274 +0x235 fp=0x7fb9c77fde40 sp=0x7fb9c77fddb0 pc=0x421555
runtime.gcDrain(0xc000036e98, 0x2)
/opt/go/src/runtime/mgcmark.go:1032 +0x1fb fp=0x7fb9c77fde98 sp=0x7fb9c77fde40 pc=0x420d5b
runtime.gcBgMarkWorker.func2()
/opt/go/src/runtime/mgc.go:1951 +0x11e fp=0x7fb9c77fded8 sp=0x7fb9c77fde98 pc=0x46383e
runtime.systemstack(0x7fb9e6ffcb70)
/opt/go/src/runtime/asm_amd64.s:370 +0x66 fp=0x7fb9c77fdee0 sp=0x7fb9c77fded8 pc=0x466976
runtime.mstart()
/opt/go/src/runtime/proc.go:1041 fp=0x7fb9c77fdee8 sp=0x7fb9c77fdee0 pc=0x43af10
I don't use unsafe or cgo in my program directly, though some of my transitive dependencies might, I can't say for sure.